Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Fri, Feb 8, 2019 at 10:52 AM Souptick Joarder wrote:
>
> On Thu, Feb 7, 2019 at 10:17 PM Matthew Wilcox wrote:
> >
> > On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote:
> > > Just thought to take opinion for documentation before placing it in v3.
> > > Does it looks fine ?
> > >
> > > +/**
> > > + * __vm_insert_range - insert range of kernel pages into user vma
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + * @offset: user's requested vm_pgoff
> > > + *
> > > + * This allow drivers to insert range of kernel pages into a user vma.
> > > + *
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +static int __vm_insert_range(struct vm_area_struct *vma, struct page
> > > **pages,
> > > + unsigned long num, unsigned long offset)
> >
> > For static functions, I prefer to leave off the second '*', ie make it
> > formatted like a docbook comment, but not be processed like a docbook
> > comment. That avoids cluttering the html with descriptions of internal
> > functions that people can't actually call.
> >
> > > +/**
> > > + * vm_insert_range - insert range of kernel pages starts with non zero
> > > offset
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + *
> > > + * Maps an object consisting of `num' `pages', catering for the user's
> >
> > Rather than using `num', you should use @num.
> >
> > > + * requested vm_pgoff
> > > + *
> > > + * If we fail to insert any page into the vma, the function will return
> > > + * immediately leaving any previously inserted pages present. Callers
> > > + * from the mmap handler may immediately return the error as their caller
> > > + * will destroy the vma, removing any successfully inserted pages. Other
> > > + * callers should make their own arrangements for calling unmap_region().
> > > + *
> > > + * Context: Process context. Called by mmap handlers.
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > > + unsigned long num)
> > >
> > >
> > > +/**
> > > + * vm_insert_range_buggy - insert range of kernel pages starts with zero
> > > offset
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + *
> > > + * Similar to vm_insert_range(), except that it explicitly sets
> > > @vm_pgoff to
> >
> > But vm_pgoff isn't a parameter, so it's misleading to format it as such.
> >
> > > + * 0. This function is intended for the drivers that did not consider
> > > + * @vm_pgoff.
> > > + *
> > > + * Context: Process context. Called by mmap handlers.
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page
> > > **pages,
> > > + unsigned long num)
> >
> > I don't think we should call it 'buggy'. 'zero' would make more sense
> > as a suffix.
>
> suffix can be *zero or zero_offset* whichever suits better.
>
> >
> > Given how this interface has evolved, I'm no longer sure than
> > 'vm_insert_range' makes sense as the name for it. Is it perhaps
> > 'vm_map_object' or 'vm_map_pages'?
> >
>
> I prefer vm_map_pages. Considering it, both the interface name can be changed
> to *vm_insert_range -> vm_map_pages* and *vm_insert_range_buggy ->
> vm_map_pages_{zero/zero_offset}.
>
> As this is only change in interface name and rest of code remain same
> shall I post it in v3 ( with additional change log mentioned about interface
> name changed) ?
>
> or,
>
> It will be a new patch series ( with carry forward all the Reviewed-by
> / Tested-by on
> vm_insert_range/ vm_insert_range_buggy ) ?
Any suggestion on this minor query ?
___
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Feb 7, 2019 at 10:17 PM Matthew Wilcox wrote:
>
> On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote:
> > Just thought to take opinion for documentation before placing it in v3.
> > Does it looks fine ?
> >
> > +/**
> > + * __vm_insert_range - insert range of kernel pages into user vma
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + * @offset: user's requested vm_pgoff
> > + *
> > + * This allow drivers to insert range of kernel pages into a user vma.
> > + *
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +static int __vm_insert_range(struct vm_area_struct *vma, struct page
> > **pages,
> > + unsigned long num, unsigned long offset)
>
> For static functions, I prefer to leave off the second '*', ie make it
> formatted like a docbook comment, but not be processed like a docbook
> comment. That avoids cluttering the html with descriptions of internal
> functions that people can't actually call.
>
> > +/**
> > + * vm_insert_range - insert range of kernel pages starts with non zero
> > offset
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + *
> > + * Maps an object consisting of `num' `pages', catering for the user's
>
> Rather than using `num', you should use @num.
>
> > + * requested vm_pgoff
> > + *
> > + * If we fail to insert any page into the vma, the function will return
> > + * immediately leaving any previously inserted pages present. Callers
> > + * from the mmap handler may immediately return the error as their caller
> > + * will destroy the vma, removing any successfully inserted pages. Other
> > + * callers should make their own arrangements for calling unmap_region().
> > + *
> > + * Context: Process context. Called by mmap handlers.
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num)
> >
> >
> > +/**
> > + * vm_insert_range_buggy - insert range of kernel pages starts with zero
> > offset
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + *
> > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff
> > to
>
> But vm_pgoff isn't a parameter, so it's misleading to format it as such.
>
> > + * 0. This function is intended for the drivers that did not consider
> > + * @vm_pgoff.
> > + *
> > + * Context: Process context. Called by mmap handlers.
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num)
>
> I don't think we should call it 'buggy'. 'zero' would make more sense
> as a suffix.
suffix can be *zero or zero_offset* whichever suits better.
>
> Given how this interface has evolved, I'm no longer sure than
> 'vm_insert_range' makes sense as the name for it. Is it perhaps
> 'vm_map_object' or 'vm_map_pages'?
>
I prefer vm_map_pages. Considering it, both the interface name can be changed
to *vm_insert_range -> vm_map_pages* and *vm_insert_range_buggy ->
vm_map_pages_{zero/zero_offset}.
As this is only change in interface name and rest of code remain same
shall I post it in v3 ( with additional change log mentioned about interface
name changed) ?
or,
It will be a new patch series ( with carry forward all the Reviewed-by
/ Tested-by on
vm_insert_range/ vm_insert_range_buggy ) ?
___
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote: > Just thought to take opinion for documentation before placing it in v3. > Does it looks fine ? > > +/** > + * __vm_insert_range - insert range of kernel pages into user vma > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * @offset: user's requested vm_pgoff > + * > + * This allow drivers to insert range of kernel pages into a user vma. > + * > + * Return: 0 on success and error code otherwise. > + */ > +static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num, unsigned long offset) For static functions, I prefer to leave off the second '*', ie make it formatted like a docbook comment, but not be processed like a docbook comment. That avoids cluttering the html with descriptions of internal functions that people can't actually call. > +/** > + * vm_insert_range - insert range of kernel pages starts with non zero offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Maps an object consisting of `num' `pages', catering for the user's Rather than using `num', you should use @num. > + * requested vm_pgoff > + * > + * If we fail to insert any page into the vma, the function will return > + * immediately leaving any previously inserted pages present. Callers > + * from the mmap handler may immediately return the error as their caller > + * will destroy the vma, removing any successfully inserted pages. Other > + * callers should make their own arrangements for calling unmap_region(). > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) > > > +/** > + * vm_insert_range_buggy - insert range of kernel pages starts with zero > offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff to But vm_pgoff isn't a parameter, so it's misleading to format it as such. > + * 0. This function is intended for the drivers that did not consider > + * @vm_pgoff. > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) I don't think we should call it 'buggy'. 'zero' would make more sense as a suffix. Given how this interface has evolved, I'm no longer sure than 'vm_insert_range' makes sense as the name for it. Is it perhaps 'vm_map_object' or 'vm_map_pages'? ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Feb 07, 2019 at 09:37:08PM +0530, Souptick Joarder wrote: > On Thu, Feb 7, 2019 at 9:27 PM Mike Rapoport wrote: > > > > Hi Souptick, > > > > On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote: > > > Hi Mike, > > > > > > Just thought to take opinion for documentation before placing it in v3. > > > Does it looks fine ? > > > > Overall looks good to me. Several minor points below. > > Thanks Mike. Noted. > Shall I consider it as *Reviewed-by:* with below changes ? Yeah, sure. > > > > > +/** > > > + * __vm_insert_range - insert range of kernel pages into user vma > > > + * @vma: user vma to map to > > > + * @pages: pointer to array of source kernel pages > > > + * @num: number of pages in page array > > > + * @offset: user's requested vm_pgoff > > > + * > > > + * This allow drivers to insert range of kernel pages into a user vma. > > > > allows > > > + * > > > + * Return: 0 on success and error code otherwise. > > > + */ > > > +static int __vm_insert_range(struct vm_area_struct *vma, struct page > > > **pages, > > > + unsigned long num, unsigned long offset) > > > > > > > > > +/** > > > + * vm_insert_range - insert range of kernel pages starts with non zero > > > offset > > > + * @vma: user vma to map to > > > + * @pages: pointer to array of source kernel pages > > > + * @num: number of pages in page array > > > + * > > > + * Maps an object consisting of `num' `pages', catering for the user's > >@num pages > > > + * requested vm_pgoff > > > + * > > > + * If we fail to insert any page into the vma, the function will return > > > + * immediately leaving any previously inserted pages present. Callers > > > + * from the mmap handler may immediately return the error as their caller > > > + * will destroy the vma, removing any successfully inserted pages. Other > > > + * callers should make their own arrangements for calling unmap_region(). > > > + * > > > + * Context: Process context. Called by mmap handlers. > > > + * Return: 0 on success and error code otherwise. > > > + */ > > > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages, > > > + unsigned long num) > > > > > > > > > +/** > > > + * vm_insert_range_buggy - insert range of kernel pages starts with zero > > > offset > > > + * @vma: user vma to map to > > > + * @pages: pointer to array of source kernel pages > > > + * @num: number of pages in page array > > > + * > > > + * Similar to vm_insert_range(), except that it explicitly sets > > > @vm_pgoff to > > > > the offset > > > > > + * 0. This function is intended for the drivers that did not consider > > > + * @vm_pgoff. > > > + * > > > + * Context: Process context. Called by mmap handlers. > > > + * Return: 0 on success and error code otherwise. > > > + */ > > > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page > > > **pages, > > > + unsigned long num) > > > > > > > -- > > Sincerely yours, > > Mike. > > > -- Sincerely yours, Mike. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Feb 7, 2019 at 9:27 PM Mike Rapoport wrote: > > Hi Souptick, > > On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote: > > Hi Mike, > > > > Just thought to take opinion for documentation before placing it in v3. > > Does it looks fine ? > > Overall looks good to me. Several minor points below. Thanks Mike. Noted. Shall I consider it as *Reviewed-by:* with below changes ? > > > +/** > > + * __vm_insert_range - insert range of kernel pages into user vma > > + * @vma: user vma to map to > > + * @pages: pointer to array of source kernel pages > > + * @num: number of pages in page array > > + * @offset: user's requested vm_pgoff > > + * > > + * This allow drivers to insert range of kernel pages into a user vma. > > allows > > + * > > + * Return: 0 on success and error code otherwise. > > + */ > > +static int __vm_insert_range(struct vm_area_struct *vma, struct page > > **pages, > > + unsigned long num, unsigned long offset) > > > > > > +/** > > + * vm_insert_range - insert range of kernel pages starts with non zero > > offset > > + * @vma: user vma to map to > > + * @pages: pointer to array of source kernel pages > > + * @num: number of pages in page array > > + * > > + * Maps an object consisting of `num' `pages', catering for the user's >@num pages > > + * requested vm_pgoff > > + * > > + * If we fail to insert any page into the vma, the function will return > > + * immediately leaving any previously inserted pages present. Callers > > + * from the mmap handler may immediately return the error as their caller > > + * will destroy the vma, removing any successfully inserted pages. Other > > + * callers should make their own arrangements for calling unmap_region(). > > + * > > + * Context: Process context. Called by mmap handlers. > > + * Return: 0 on success and error code otherwise. > > + */ > > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages, > > + unsigned long num) > > > > > > +/** > > + * vm_insert_range_buggy - insert range of kernel pages starts with zero > > offset > > + * @vma: user vma to map to > > + * @pages: pointer to array of source kernel pages > > + * @num: number of pages in page array > > + * > > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff > > to > > the offset > > > + * 0. This function is intended for the drivers that did not consider > > + * @vm_pgoff. > > + * > > + * Context: Process context. Called by mmap handlers. > > + * Return: 0 on success and error code otherwise. > > + */ > > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages, > > + unsigned long num) > > > > -- > Sincerely yours, > Mike. > ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
Hi Souptick, On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote: > Hi Mike, > > Just thought to take opinion for documentation before placing it in v3. > Does it looks fine ? Overall looks good to me. Several minor points below. > +/** > + * __vm_insert_range - insert range of kernel pages into user vma > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * @offset: user's requested vm_pgoff > + * > + * This allow drivers to insert range of kernel pages into a user vma. allows > + * > + * Return: 0 on success and error code otherwise. > + */ > +static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num, unsigned long offset) > > > +/** > + * vm_insert_range - insert range of kernel pages starts with non zero offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Maps an object consisting of `num' `pages', catering for the user's @num pages > + * requested vm_pgoff > + * > + * If we fail to insert any page into the vma, the function will return > + * immediately leaving any previously inserted pages present. Callers > + * from the mmap handler may immediately return the error as their caller > + * will destroy the vma, removing any successfully inserted pages. Other > + * callers should make their own arrangements for calling unmap_region(). > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) > > > +/** > + * vm_insert_range_buggy - insert range of kernel pages starts with zero > offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff to the offset > + * 0. This function is intended for the drivers that did not consider > + * @vm_pgoff. > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) > -- Sincerely yours, Mike. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
Hi Mike,
On Thu, Jan 31, 2019 at 2:09 PM Mike Rapoport wrote:
>
> On Thu, Jan 31, 2019 at 08:38:12AM +0530, Souptick Joarder wrote:
> > Previouly drivers have their own way of mapping range of
> > kernel pages/memory into user vma and this was done by
> > invoking vm_insert_page() within a loop.
> >
> > As this pattern is common across different drivers, it can
> > be generalized by creating new functions and use it across
> > the drivers.
> >
> > vm_insert_range() is the API which could be used to mapped
> > kernel memory/pages in drivers which has considered vm_pgoff
> >
> > vm_insert_range_buggy() is the API which could be used to map
> > range of kernel memory/pages in drivers which has not considered
> > vm_pgoff. vm_pgoff is passed default as 0 for those drivers.
> >
> > We _could_ then at a later "fix" these drivers which are using
> > vm_insert_range_buggy() to behave according to the normal vm_pgoff
> > offsetting simply by removing the _buggy suffix on the function
> > name and if that causes regressions, it gives us an easy way to revert.
> >
> > Signed-off-by: Souptick Joarder
> > Suggested-by: Russell King
> > Suggested-by: Matthew Wilcox
> > ---
> > include/linux/mm.h | 4 +++
> > mm/memory.c| 81
> > ++
> > mm/nommu.c | 14 ++
> > 3 files changed, 99 insertions(+)
> >
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 80bb640..25752b0 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct vm_area_struct
> > *vma,
> > int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
> > unsigned long pfn, unsigned long size, pgprot_t);
> > int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct
> > page *);
> > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num);
> > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num);
> > vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> > unsigned long pfn);
> > vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long
> > addr,
> > diff --git a/mm/memory.c b/mm/memory.c
> > index e11ca9d..0a4bf57 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma,
> > unsigned long addr,
> > }
> > EXPORT_SYMBOL(vm_insert_page);
> >
> > +/**
> > + * __vm_insert_range - insert range of kernel pages into user vma
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + * @offset: user's requested vm_pgoff
> > + *
> > + * This allows drivers to insert range of kernel pages they've allocated
> > + * into a user vma.
> > + *
> > + * If we fail to insert any page into the vma, the function will return
> > + * immediately leaving any previously inserted pages present. Callers
> > + * from the mmap handler may immediately return the error as their caller
> > + * will destroy the vma, removing any successfully inserted pages. Other
> > + * callers should make their own arrangements for calling unmap_region().
> > + *
> > + * Context: Process context.
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +static int __vm_insert_range(struct vm_area_struct *vma, struct page
> > **pages,
> > + unsigned long num, unsigned long offset)
> > +{
> > + unsigned long count = vma_pages(vma);
> > + unsigned long uaddr = vma->vm_start;
> > + int ret, i;
> > +
> > + /* Fail if the user requested offset is beyond the end of the object
> > */
> > + if (offset > num)
> > + return -ENXIO;
> > +
> > + /* Fail if the user requested size exceeds available object size */
> > + if (count > num - offset)
> > + return -ENXIO;
> > +
> > + for (i = 0; i < count; i++) {
> > + ret = vm_insert_page(vma, uaddr, pages[offset + i]);
> > + if (ret < 0)
> > + return ret;
> > + uaddr += PAGE_SIZE;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * vm_insert_range - insert range of kernel pages starts with non zero
> > offset
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + *
> > + * Maps an object consisting of `num' `pages', catering for the user's
> > + * requested vm_pgoff
> > + *
>
> The elaborate description you've added to __vm_insert_range() is better put
> here, as this is the "public" function.
>
> > + * Context: Process context. Called by mmap handlers.
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +int vm_insert_range(struct vm_area_struct *vma,
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Jan 31, 2019 at 6:04 PM Heiko Stuebner wrote: > > Am Donnerstag, 31. Januar 2019, 13:31:52 CET schrieb Souptick Joarder: > > On Thu, Jan 31, 2019 at 5:37 PM Heiko Stuebner wrote: > > > > > > Am Donnerstag, 31. Januar 2019, 04:08:12 CET schrieb Souptick Joarder: > > > > Previouly drivers have their own way of mapping range of > > > > kernel pages/memory into user vma and this was done by > > > > invoking vm_insert_page() within a loop. > > > > > > > > As this pattern is common across different drivers, it can > > > > be generalized by creating new functions and use it across > > > > the drivers. > > > > > > > > vm_insert_range() is the API which could be used to mapped > > > > kernel memory/pages in drivers which has considered vm_pgoff > > > > > > > > vm_insert_range_buggy() is the API which could be used to map > > > > range of kernel memory/pages in drivers which has not considered > > > > vm_pgoff. vm_pgoff is passed default as 0 for those drivers. > > > > > > > > We _could_ then at a later "fix" these drivers which are using > > > > vm_insert_range_buggy() to behave according to the normal vm_pgoff > > > > offsetting simply by removing the _buggy suffix on the function > > > > name and if that causes regressions, it gives us an easy way to revert. > > > > > > > > Signed-off-by: Souptick Joarder > > > > Suggested-by: Russell King > > > > Suggested-by: Matthew Wilcox > > > > > > hmm, I'm missing a changelog here between v1 and v2. > > > Nevertheless I managed to test v1 on Rockchip hardware > > > and display is still working, including talking to Lima via prime. > > > > > > So if there aren't any big changes for v2, on Rockchip > > > Tested-by: Heiko Stuebner > > > > Change log is available in [0/9]. > > Patch [1/9] & [4/9] have no changes between v1 -> v2. > > I never seem to get your cover-letters, so didn't see that, sorry. I added you in sender list for all cover-letters but it didn't reach your inbox :-) Thanks for reviewing and validating the patch. > > But great that there weren't changes then :-) > > Heiko > > ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
Am Donnerstag, 31. Januar 2019, 13:31:52 CET schrieb Souptick Joarder: > On Thu, Jan 31, 2019 at 5:37 PM Heiko Stuebner wrote: > > > > Am Donnerstag, 31. Januar 2019, 04:08:12 CET schrieb Souptick Joarder: > > > Previouly drivers have their own way of mapping range of > > > kernel pages/memory into user vma and this was done by > > > invoking vm_insert_page() within a loop. > > > > > > As this pattern is common across different drivers, it can > > > be generalized by creating new functions and use it across > > > the drivers. > > > > > > vm_insert_range() is the API which could be used to mapped > > > kernel memory/pages in drivers which has considered vm_pgoff > > > > > > vm_insert_range_buggy() is the API which could be used to map > > > range of kernel memory/pages in drivers which has not considered > > > vm_pgoff. vm_pgoff is passed default as 0 for those drivers. > > > > > > We _could_ then at a later "fix" these drivers which are using > > > vm_insert_range_buggy() to behave according to the normal vm_pgoff > > > offsetting simply by removing the _buggy suffix on the function > > > name and if that causes regressions, it gives us an easy way to revert. > > > > > > Signed-off-by: Souptick Joarder > > > Suggested-by: Russell King > > > Suggested-by: Matthew Wilcox > > > > hmm, I'm missing a changelog here between v1 and v2. > > Nevertheless I managed to test v1 on Rockchip hardware > > and display is still working, including talking to Lima via prime. > > > > So if there aren't any big changes for v2, on Rockchip > > Tested-by: Heiko Stuebner > > Change log is available in [0/9]. > Patch [1/9] & [4/9] have no changes between v1 -> v2. I never seem to get your cover-letters, so didn't see that, sorry. But great that there weren't changes then :-) Heiko ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Jan 31, 2019 at 5:37 PM Heiko Stuebner wrote: > > Am Donnerstag, 31. Januar 2019, 04:08:12 CET schrieb Souptick Joarder: > > Previouly drivers have their own way of mapping range of > > kernel pages/memory into user vma and this was done by > > invoking vm_insert_page() within a loop. > > > > As this pattern is common across different drivers, it can > > be generalized by creating new functions and use it across > > the drivers. > > > > vm_insert_range() is the API which could be used to mapped > > kernel memory/pages in drivers which has considered vm_pgoff > > > > vm_insert_range_buggy() is the API which could be used to map > > range of kernel memory/pages in drivers which has not considered > > vm_pgoff. vm_pgoff is passed default as 0 for those drivers. > > > > We _could_ then at a later "fix" these drivers which are using > > vm_insert_range_buggy() to behave according to the normal vm_pgoff > > offsetting simply by removing the _buggy suffix on the function > > name and if that causes regressions, it gives us an easy way to revert. > > > > Signed-off-by: Souptick Joarder > > Suggested-by: Russell King > > Suggested-by: Matthew Wilcox > > hmm, I'm missing a changelog here between v1 and v2. > Nevertheless I managed to test v1 on Rockchip hardware > and display is still working, including talking to Lima via prime. > > So if there aren't any big changes for v2, on Rockchip > Tested-by: Heiko Stuebner Change log is available in [0/9]. Patch [1/9] & [4/9] have no changes between v1 -> v2. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
Am Donnerstag, 31. Januar 2019, 04:08:12 CET schrieb Souptick Joarder: > Previouly drivers have their own way of mapping range of > kernel pages/memory into user vma and this was done by > invoking vm_insert_page() within a loop. > > As this pattern is common across different drivers, it can > be generalized by creating new functions and use it across > the drivers. > > vm_insert_range() is the API which could be used to mapped > kernel memory/pages in drivers which has considered vm_pgoff > > vm_insert_range_buggy() is the API which could be used to map > range of kernel memory/pages in drivers which has not considered > vm_pgoff. vm_pgoff is passed default as 0 for those drivers. > > We _could_ then at a later "fix" these drivers which are using > vm_insert_range_buggy() to behave according to the normal vm_pgoff > offsetting simply by removing the _buggy suffix on the function > name and if that causes regressions, it gives us an easy way to revert. > > Signed-off-by: Souptick Joarder > Suggested-by: Russell King > Suggested-by: Matthew Wilcox hmm, I'm missing a changelog here between v1 and v2. Nevertheless I managed to test v1 on Rockchip hardware and display is still working, including talking to Lima via prime. So if there aren't any big changes for v2, on Rockchip Tested-by: Heiko Stuebner Heiko ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Jan 31, 2019 at 03:43:39PM +0530, Souptick Joarder wrote:
> On Thu, Jan 31, 2019 at 2:09 PM Mike Rapoport wrote:
> >
> > On Thu, Jan 31, 2019 at 08:38:12AM +0530, Souptick Joarder wrote:
> > > Previouly drivers have their own way of mapping range of
> > > kernel pages/memory into user vma and this was done by
> > > invoking vm_insert_page() within a loop.
> > >
> > > As this pattern is common across different drivers, it can
> > > be generalized by creating new functions and use it across
> > > the drivers.
> > >
> > > vm_insert_range() is the API which could be used to mapped
> > > kernel memory/pages in drivers which has considered vm_pgoff
> > >
> > > vm_insert_range_buggy() is the API which could be used to map
> > > range of kernel memory/pages in drivers which has not considered
> > > vm_pgoff. vm_pgoff is passed default as 0 for those drivers.
> > >
> > > We _could_ then at a later "fix" these drivers which are using
> > > vm_insert_range_buggy() to behave according to the normal vm_pgoff
> > > offsetting simply by removing the _buggy suffix on the function
> > > name and if that causes regressions, it gives us an easy way to revert.
> > >
> > > Signed-off-by: Souptick Joarder
> > > Suggested-by: Russell King
> > > Suggested-by: Matthew Wilcox
> > > ---
> > > include/linux/mm.h | 4 +++
> > > mm/memory.c| 81
> > > ++
> > > mm/nommu.c | 14 ++
> > > 3 files changed, 99 insertions(+)
> > >
> > > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > > index 80bb640..25752b0 100644
> > > --- a/include/linux/mm.h
> > > +++ b/include/linux/mm.h
> > > @@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct
> > > vm_area_struct *vma,
> > > int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
> > > unsigned long pfn, unsigned long size, pgprot_t);
> > > int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct
> > > page *);
> > > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > > + unsigned long num);
> > > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page
> > > **pages,
> > > + unsigned long num);
> > > vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> > > unsigned long pfn);
> > > vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long
> > > addr,
> > > diff --git a/mm/memory.c b/mm/memory.c
> > > index e11ca9d..0a4bf57 100644
> > > --- a/mm/memory.c
> > > +++ b/mm/memory.c
> > > @@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma,
> > > unsigned long addr,
> > > }
> > > EXPORT_SYMBOL(vm_insert_page);
> > >
> > > +/**
> > > + * __vm_insert_range - insert range of kernel pages into user vma
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + * @offset: user's requested vm_pgoff
> > > + *
> > > + * This allows drivers to insert range of kernel pages they've allocated
> > > + * into a user vma.
> > > + *
> > > + * If we fail to insert any page into the vma, the function will return
> > > + * immediately leaving any previously inserted pages present. Callers
> > > + * from the mmap handler may immediately return the error as their caller
> > > + * will destroy the vma, removing any successfully inserted pages. Other
> > > + * callers should make their own arrangements for calling unmap_region().
> > > + *
> > > + * Context: Process context.
> > > + * Return: 0 on success and error code otherwise.
> > > + */
> > > +static int __vm_insert_range(struct vm_area_struct *vma, struct page
> > > **pages,
> > > + unsigned long num, unsigned long offset)
> > > +{
> > > + unsigned long count = vma_pages(vma);
> > > + unsigned long uaddr = vma->vm_start;
> > > + int ret, i;
> > > +
> > > + /* Fail if the user requested offset is beyond the end of the
> > > object */
> > > + if (offset > num)
> > > + return -ENXIO;
> > > +
> > > + /* Fail if the user requested size exceeds available object size */
> > > + if (count > num - offset)
> > > + return -ENXIO;
> > > +
> > > + for (i = 0; i < count; i++) {
> > > + ret = vm_insert_page(vma, uaddr, pages[offset + i]);
> > > + if (ret < 0)
> > > + return ret;
> > > + uaddr += PAGE_SIZE;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +/**
> > > + * vm_insert_range - insert range of kernel pages starts with non zero
> > > offset
> > > + * @vma: user vma to map to
> > > + * @pages: pointer to array of source kernel pages
> > > + * @num: number of pages in page array
> > > + *
> > > + * Maps an object consisting of `num' `pages', catering for the user's
> > > + * requested vm_pgoff
> > > + *
> >
> >
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Jan 31, 2019 at 2:09 PM Mike Rapoport wrote:
>
> On Thu, Jan 31, 2019 at 08:38:12AM +0530, Souptick Joarder wrote:
> > Previouly drivers have their own way of mapping range of
> > kernel pages/memory into user vma and this was done by
> > invoking vm_insert_page() within a loop.
> >
> > As this pattern is common across different drivers, it can
> > be generalized by creating new functions and use it across
> > the drivers.
> >
> > vm_insert_range() is the API which could be used to mapped
> > kernel memory/pages in drivers which has considered vm_pgoff
> >
> > vm_insert_range_buggy() is the API which could be used to map
> > range of kernel memory/pages in drivers which has not considered
> > vm_pgoff. vm_pgoff is passed default as 0 for those drivers.
> >
> > We _could_ then at a later "fix" these drivers which are using
> > vm_insert_range_buggy() to behave according to the normal vm_pgoff
> > offsetting simply by removing the _buggy suffix on the function
> > name and if that causes regressions, it gives us an easy way to revert.
> >
> > Signed-off-by: Souptick Joarder
> > Suggested-by: Russell King
> > Suggested-by: Matthew Wilcox
> > ---
> > include/linux/mm.h | 4 +++
> > mm/memory.c| 81
> > ++
> > mm/nommu.c | 14 ++
> > 3 files changed, 99 insertions(+)
> >
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 80bb640..25752b0 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct vm_area_struct
> > *vma,
> > int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
> > unsigned long pfn, unsigned long size, pgprot_t);
> > int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct
> > page *);
> > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num);
> > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
> > + unsigned long num);
> > vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> > unsigned long pfn);
> > vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long
> > addr,
> > diff --git a/mm/memory.c b/mm/memory.c
> > index e11ca9d..0a4bf57 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma,
> > unsigned long addr,
> > }
> > EXPORT_SYMBOL(vm_insert_page);
> >
> > +/**
> > + * __vm_insert_range - insert range of kernel pages into user vma
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + * @offset: user's requested vm_pgoff
> > + *
> > + * This allows drivers to insert range of kernel pages they've allocated
> > + * into a user vma.
> > + *
> > + * If we fail to insert any page into the vma, the function will return
> > + * immediately leaving any previously inserted pages present. Callers
> > + * from the mmap handler may immediately return the error as their caller
> > + * will destroy the vma, removing any successfully inserted pages. Other
> > + * callers should make their own arrangements for calling unmap_region().
> > + *
> > + * Context: Process context.
> > + * Return: 0 on success and error code otherwise.
> > + */
> > +static int __vm_insert_range(struct vm_area_struct *vma, struct page
> > **pages,
> > + unsigned long num, unsigned long offset)
> > +{
> > + unsigned long count = vma_pages(vma);
> > + unsigned long uaddr = vma->vm_start;
> > + int ret, i;
> > +
> > + /* Fail if the user requested offset is beyond the end of the object
> > */
> > + if (offset > num)
> > + return -ENXIO;
> > +
> > + /* Fail if the user requested size exceeds available object size */
> > + if (count > num - offset)
> > + return -ENXIO;
> > +
> > + for (i = 0; i < count; i++) {
> > + ret = vm_insert_page(vma, uaddr, pages[offset + i]);
> > + if (ret < 0)
> > + return ret;
> > + uaddr += PAGE_SIZE;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * vm_insert_range - insert range of kernel pages starts with non zero
> > offset
> > + * @vma: user vma to map to
> > + * @pages: pointer to array of source kernel pages
> > + * @num: number of pages in page array
> > + *
> > + * Maps an object consisting of `num' `pages', catering for the user's
> > + * requested vm_pgoff
> > + *
>
> The elaborate description you've added to __vm_insert_range() is better put
> here, as this is the "public" function.
Ok, will add it in v3. Which means __vm_insert_range() still needs a short
description ?
>
> > + * Context: Process context. Called by mmap handlers.
> > + * Return: 0 on success and error
Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
On Thu, Jan 31, 2019 at 08:38:12AM +0530, Souptick Joarder wrote:
> Previouly drivers have their own way of mapping range of
> kernel pages/memory into user vma and this was done by
> invoking vm_insert_page() within a loop.
>
> As this pattern is common across different drivers, it can
> be generalized by creating new functions and use it across
> the drivers.
>
> vm_insert_range() is the API which could be used to mapped
> kernel memory/pages in drivers which has considered vm_pgoff
>
> vm_insert_range_buggy() is the API which could be used to map
> range of kernel memory/pages in drivers which has not considered
> vm_pgoff. vm_pgoff is passed default as 0 for those drivers.
>
> We _could_ then at a later "fix" these drivers which are using
> vm_insert_range_buggy() to behave according to the normal vm_pgoff
> offsetting simply by removing the _buggy suffix on the function
> name and if that causes regressions, it gives us an easy way to revert.
>
> Signed-off-by: Souptick Joarder
> Suggested-by: Russell King
> Suggested-by: Matthew Wilcox
> ---
> include/linux/mm.h | 4 +++
> mm/memory.c| 81
> ++
> mm/nommu.c | 14 ++
> 3 files changed, 99 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 80bb640..25752b0 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct vm_area_struct
> *vma,
> int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
> unsigned long pfn, unsigned long size, pgprot_t);
> int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page
> *);
> +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> + unsigned long num);
> +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
> + unsigned long num);
> vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> unsigned long pfn);
> vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long
> addr,
> diff --git a/mm/memory.c b/mm/memory.c
> index e11ca9d..0a4bf57 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma,
> unsigned long addr,
> }
> EXPORT_SYMBOL(vm_insert_page);
>
> +/**
> + * __vm_insert_range - insert range of kernel pages into user vma
> + * @vma: user vma to map to
> + * @pages: pointer to array of source kernel pages
> + * @num: number of pages in page array
> + * @offset: user's requested vm_pgoff
> + *
> + * This allows drivers to insert range of kernel pages they've allocated
> + * into a user vma.
> + *
> + * If we fail to insert any page into the vma, the function will return
> + * immediately leaving any previously inserted pages present. Callers
> + * from the mmap handler may immediately return the error as their caller
> + * will destroy the vma, removing any successfully inserted pages. Other
> + * callers should make their own arrangements for calling unmap_region().
> + *
> + * Context: Process context.
> + * Return: 0 on success and error code otherwise.
> + */
> +static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> + unsigned long num, unsigned long offset)
> +{
> + unsigned long count = vma_pages(vma);
> + unsigned long uaddr = vma->vm_start;
> + int ret, i;
> +
> + /* Fail if the user requested offset is beyond the end of the object */
> + if (offset > num)
> + return -ENXIO;
> +
> + /* Fail if the user requested size exceeds available object size */
> + if (count > num - offset)
> + return -ENXIO;
> +
> + for (i = 0; i < count; i++) {
> + ret = vm_insert_page(vma, uaddr, pages[offset + i]);
> + if (ret < 0)
> + return ret;
> + uaddr += PAGE_SIZE;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * vm_insert_range - insert range of kernel pages starts with non zero offset
> + * @vma: user vma to map to
> + * @pages: pointer to array of source kernel pages
> + * @num: number of pages in page array
> + *
> + * Maps an object consisting of `num' `pages', catering for the user's
> + * requested vm_pgoff
> + *
The elaborate description you've added to __vm_insert_range() is better put
here, as this is the "public" function.
> + * Context: Process context. Called by mmap handlers.
> + * Return: 0 on success and error code otherwise.
> + */
> +int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
> + unsigned long num)
> +{
> + return __vm_insert_range(vma, pages, num, vma->vm_pgoff);
> +}
> +EXPORT_SYMBOL(vm_insert_range);
> +
> +/**
> + * vm_insert_range_buggy - insert range of kernel pages starts with zero
> offset
> + * @vma: user vma to map to
>
[PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API
Previouly drivers have their own way of mapping range of
kernel pages/memory into user vma and this was done by
invoking vm_insert_page() within a loop.
As this pattern is common across different drivers, it can
be generalized by creating new functions and use it across
the drivers.
vm_insert_range() is the API which could be used to mapped
kernel memory/pages in drivers which has considered vm_pgoff
vm_insert_range_buggy() is the API which could be used to map
range of kernel memory/pages in drivers which has not considered
vm_pgoff. vm_pgoff is passed default as 0 for those drivers.
We _could_ then at a later "fix" these drivers which are using
vm_insert_range_buggy() to behave according to the normal vm_pgoff
offsetting simply by removing the _buggy suffix on the function
name and if that causes regressions, it gives us an easy way to revert.
Signed-off-by: Souptick Joarder
Suggested-by: Russell King
Suggested-by: Matthew Wilcox
---
include/linux/mm.h | 4 +++
mm/memory.c| 81 ++
mm/nommu.c | 14 ++
3 files changed, 99 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 80bb640..25752b0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2565,6 +2565,10 @@ unsigned long change_prot_numa(struct vm_area_struct
*vma,
int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
unsigned long pfn, unsigned long size, pgprot_t);
int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
+int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
+ unsigned long num);
+int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
+ unsigned long num);
vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index e11ca9d..0a4bf57 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1520,6 +1520,87 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned
long addr,
}
EXPORT_SYMBOL(vm_insert_page);
+/**
+ * __vm_insert_range - insert range of kernel pages into user vma
+ * @vma: user vma to map to
+ * @pages: pointer to array of source kernel pages
+ * @num: number of pages in page array
+ * @offset: user's requested vm_pgoff
+ *
+ * This allows drivers to insert range of kernel pages they've allocated
+ * into a user vma.
+ *
+ * If we fail to insert any page into the vma, the function will return
+ * immediately leaving any previously inserted pages present. Callers
+ * from the mmap handler may immediately return the error as their caller
+ * will destroy the vma, removing any successfully inserted pages. Other
+ * callers should make their own arrangements for calling unmap_region().
+ *
+ * Context: Process context.
+ * Return: 0 on success and error code otherwise.
+ */
+static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages,
+ unsigned long num, unsigned long offset)
+{
+ unsigned long count = vma_pages(vma);
+ unsigned long uaddr = vma->vm_start;
+ int ret, i;
+
+ /* Fail if the user requested offset is beyond the end of the object */
+ if (offset > num)
+ return -ENXIO;
+
+ /* Fail if the user requested size exceeds available object size */
+ if (count > num - offset)
+ return -ENXIO;
+
+ for (i = 0; i < count; i++) {
+ ret = vm_insert_page(vma, uaddr, pages[offset + i]);
+ if (ret < 0)
+ return ret;
+ uaddr += PAGE_SIZE;
+ }
+
+ return 0;
+}
+
+/**
+ * vm_insert_range - insert range of kernel pages starts with non zero offset
+ * @vma: user vma to map to
+ * @pages: pointer to array of source kernel pages
+ * @num: number of pages in page array
+ *
+ * Maps an object consisting of `num' `pages', catering for the user's
+ * requested vm_pgoff
+ *
+ * Context: Process context. Called by mmap handlers.
+ * Return: 0 on success and error code otherwise.
+ */
+int vm_insert_range(struct vm_area_struct *vma, struct page **pages,
+ unsigned long num)
+{
+ return __vm_insert_range(vma, pages, num, vma->vm_pgoff);
+}
+EXPORT_SYMBOL(vm_insert_range);
+
+/**
+ * vm_insert_range_buggy - insert range of kernel pages starts with zero offset
+ * @vma: user vma to map to
+ * @pages: pointer to array of source kernel pages
+ * @num: number of pages in page array
+ *
+ * Maps a set of pages, always starting at page[0]
+ *
+ * Context: Process context. Called by mmap handlers.
+ * Return: 0 on success and error code otherwise.
+ */
+int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages,
+ unsigned long num)
